Muscle Fibers, HIT, and more

[Powerlifter16]

Hope y'all enjoy and read these pieces from Mel Siff. Took me awhile to type all this up.


lifter

[Deciever]

Muscle Fibers and Training
“SuperTraining” Pg.57-60

Fiber types differ considerably between individuals, especially between endurance and strength athletes. For instance, vastus medialis biopsies reveal that the proportion of FT fibers in field athletes and weightlifters can be over tree times (i.e. over 60% FT fibers) greater then that of marathon runners (approximately 17% FT fibers) and 50% greater than that of bodybuilders, cyclist and race walkers (all about 40% FT fibers). The importance of fast fibers in short duration explosive or maximal strength efforts is underscored by the fact that fast type IIX fibers contract 10x's faster than slower type I fibers (Anderson et al, 2000)
Near-maximal and explosive resistance training also produces greater hypertrophy of FT fibers than ST fibers (Hakkinen, 1985). In this respect it is noteworthy that maximal muscles power output and potential for explosive movements is determined strongly by the proportion of FT fibers in the relevant muscles (Hakkinen, 1985) Moreover, endurance training reduces vertical jump power, explosive speed and similar FT fibers activities possibly because endurance training may degrade FT fibers, replace them with ST fibers or cause enzymatic and neuromuscular changes more appropriate to slow endurance activities (Armstrong, 1987).
Although research indicates that fiber distribution is strongly determined by genetic factors, it appears as if these differences may also be strongly influenced by the type, intensity and duration of training, as well as the pre-training status of the individual. This becomes particularly evident if the muscle fiber distribution is compared between weightlifters and bodybuilders. Weightlifters have a considerably higher proportion of FT fibers, a fact which cannot explain by the contention that specific genetic types excel at specific sports. Bodybuilders have about 10% fewer FT fibers (or 10% more ST fibers) than untrained subjects, while weightlifters have about 10% more FT fibers. It is apparent that even the specific type of strength training may weightlifters and bodybuilders probably lies in the fact that weightlifters usually execute considerably more low repetition, maximal effort, explosive training than bodybuilders, who have often used moderate loads slowly to failure.
Hather et al (1991) reported that 19 wk of heavy resistance training caused a decrease in the percentage of type IIX/B and an increase in the percentage of type IIA fibers in vastus lateralis, suggesting that resistance training had caused transformation among the fast-twitch fiber subtypes. This was confirmed by further work which also showed that neither MHC I composition nor type I muscles fibers percentage changed with training (Adams et al, 1993).
One has to be cautious, in the simplistically analyzing different activities and athletes on the basis of percentage differences in muscle fiber type, since the cross-section area of all fibers is not the same and we know that force generated by a muscle depends on its cross sectional area ( as well as its level of excitation at any given instant).FT generally are about 30-40% larger in cross-section area than ST fibers (although there are notable exceptions which are discussed later). This means, even if a muscles comprises equal 50% percent of FT and ST fibers, that the overall percentage of FT contribution to total cross-section areas of the muscle can exceed 65%, depending on the degree of hypertrophy (Pipes, 1994; Tesch et al 1983). In individuals and muscles groups with a tendency to contain more FT fibers, this value can be even higher.
Furthermore, it has been found that heavy resistance training enlarges type II fibers twice as much as in slow fibers, which shows that strength training can increase the relative cross-section area of FT fibers without increasing the relative proportion of FT fibers in the muscles (Anderson & Aagaard, 200; Andersen et al, 2000). Since the velocity of muscle contraction depends on the area covered by fast fibers, an athlete may use intense strength training to increase strength and power, even if one cannot change the actual proportion of fast fibers in the muscles.
Another interesting finding in this, after a period of resistance training, MHC IIX content decreases from 9.3 to 2.0%, with a corresponding increase in MHC IIA from 42.4% to 49.6 % (Andersen & Aagarrd, 2000). After a detraining period of 3 months, the amount of MHC IIX reach values that were 17% higher than before and after resistance training, revealing that the research call MHC IIX overshoot. This seems to suggest that, if an athlete wishes to increase the relative amount of fast muscles fibers isoforms, a logical method would be to decrease the training load and allow the fastest fibers to express themselves a few weeds later. This finding appears to lend some support to practice of training ‘tapering’ that has been implemented for many years among strength and sprint athletes. It is important to that the this study was carried out on sedentary subjects that situation might be very different among elite athletes. At this stage the use of a 3 month tapering period would be regarded by all athletes as being excessive, so, if we are to be guided by the trial and error experiences of athletes, it might well be found that detraining periods need to be considerably shorter for trained competitors whose ability to distinguish between the different components of detraining, namely the perceived and actual levels of intensity and volume. In the case of heavy strength activities, it is usually excessive volume which tends to have more profound effect then occasional very heavy loads on competitive impairment. One also needs to be appreciated that the volume and intensity as calculated on a typical training card may not concur with the perceived impact of this variable, so that one should also be guided by the athlete’s perception of his condition.
Some researchers have suggested that there may be an optimal or maximum size for individual muscles fibers undergoing training hypertrophy, since efficiency of strength, power and work production decrease if muscles cross-sectional area is too small or to large ( MacDougal et al, 1982; Tesch & Larsson, 1982). Other work tends to corroborate this conclusion (Hakkinen, 1985). This study noted a significant increase in the maximal isometric strength of non-athletes, but no hypertrophy of ST or FT fibers, between weeks 12-20 of a 24 week-long strength training routine using variable intensity rates of concentric and eccentric exercise. The significant strength increase during weeks 12-20 was attributed to increase neural activation. In highly trained athletes, the increase in muscular hypertrophy is even more limited, thereby emphasizing the importance of using high intensity, rapid transition techniques for stimulating their nervous systems.
The existence of possible optimal fiber size, the limited ability of advanced athletes to experience muscle hypertrophy, and the lack of correlation between hypertrophy and strength training stresses the futility of prescribing hypertrophy training for highly qualified athletes. This type of training is suitable for novices, but its regular use may be seriously detrimental to the strength and strength-speed performance for elite athletes.
There is also considerable evidence to indicated that cardiovascular (‘aerobic’) endurance exercises performed at low intensity for long periods during the same stage of condition program as strength training seriously compromises the development of strength and power. This is probably partly due to the fact that it is relatively easy for the faster twitching fibers to become or behave like slow twitch fibers with prolonged low intensity training. Furthermore, studies of the gastrocnemius muscles of distance runners have show that prolonged distance training produces muscles necrosis and inflammation which can be detected at least 7 days after the marathon (Hakida et al, 1983). Comparative muscles biopsy studies of weightlifters, sprinters and rowers after strenuous training sessions do not show any of these abnormalities.
These findings have important consequences for the design of sport specific strength programmes, since some instructors and machine manufactures maintain that continuous circuit training (CCT) regimes simultaneously develop cardiovascular endurance and strength. Research does not support this belief. On the contrary, it shows that it is more appropriate to prescribe cardiovascular training separately in limited amounts during the early off-season and high intensity resistance training at the later stage. In addition, interval circuit training (ICT) using high intensity loading and regular rest intervals is more suitable for development of strength and strength-endurance.
The sequence of recruitment of muscles fibers by exercise also has important consequences for training. The ST (Type I) fibers are recruited first for muscle tension up to about 25%, the FTa (Type IIA) are recruited next and the FT (FF or Type IIX) fibers last, as the intensity of the activity increases towards a maximum or as the ST fibers become seriously energy depleted. (See below)

[Deciever]

Therefore, if the intention is to train FT fibers for an particular sport, it is vital that high intensity training be concentrated upon.
Further research reveals that this high intensity is not necessarily dependent on the use of 1RM (1 repetition maximum) or near 1 RM loads, but the degree to which the relevant muscles fibers are recruited during the effort. In this respect, the terms Fast twitch and Slow twitch do not necessarily mean that fast movements recruit exclusively FT fibers and the slow movements ST fibers. To analyses the involvement of different fiber types, it is vital to determine the force that needs to be produced. If large acceleration of the load is involved, Newton’s Second Law of Motion decrees that the resulting force will be large. Thus, the maximal force generated during rapid acceleration of a 100kg bench press easily can exceed that maximal force produced during a slowly accelerated 150kg bench press. Both a small load accelerated rapidly and heavy load accelerated slowly but strongly involved the FT fibers. Likewise, explosive movements rely heavily on the action of FT fibers.
Moreover, rapid movements often recruit the muscles stretch (myotatic) reflex, which can elicit a powerful contraction. Relevant to this process is Starling’s Law, which states that the strength of contraction is proportional to the original length of the muscles at the moment of contraction. The idea relationship between tension and length in a sarcomere occurs when the muscles is slight stretched and the actin and myosin filaments just overlap slightly. However, in applying this law, it has to be remembered that the advantaged offered by the stretching may be diminished in case where this stretching occurs at large joint angles which provide poor leverage. The well-known pre-stretch principle in bodybuilding training and the plyometric method in speed-strength training rely on this phenomenon. Many gymnasiums machines are seriously limiting in they do not allow the use to begin the movement with a pres-stretch. Not only does this diminish the force which can be generated, but it also exposes joints to a greater risk of injury because the movement begins without muscular support for the ligaments.
The importance of the nervous system in developing strength cannot be ignored. As stated earlier, the development of strength is related to the number of appropriate muscles fibers firing simultaneously, which is entirely a function of the nervous system. An additional finding is that, if the nerve which normally supplies a ST muscle fiber is surgically interchange (‘cross reinnervated’) with one which supplies a FT fiber, the ST fiber will behave like a FT fiber (e.g. Bacou et al, 1996; Barjot et al, 1998) These studies, carried out on rabbits, suggest that sensitivity to motor innervations increases from the glycolytic to oxidative types of fibers, in the order: IIB.IIX/IID>IIA>I ( where the IID, like the IIB fibers types occurred in small mammals as analogues of the human IIX type). In other words, the behavior of muscles would appear to be determined by the activity of the nerve fibers which supply it, a deduction which is discussed farther in the next section.
The rate of the number of fibers firing depends on the voluntary and involuntary processes, the voluntary ones being related to personal motivation and the biofeedback techniques, and the involuntary ones to feedback information from the proprioceptive system, including the various stretch reflexes.
Thus, the simple act of motivating or emotionally willing yourself, through the methods such as self-talk or guided imagery to produce greater or faster efforts can recruit a greater number of muscle fibers at an increase rate of firing. Encouragement by a training partner can also play a useful role in this regard, if done at the appropriate stages during an exercise. Interestingly, the method of training with progressively higher loads or at larger acceleration is a valuable way of learning how to motivate yourself at progressively higher levels of performance. The carry-over of this may well benefit one in all aspects of daily life.



Cheating methods should never be used with any exercise: (F&F pg. 229)
All to often there is a fanatical overemphasis on the use of ‘strict’ exercise style to enhance effectiveness and safety. ‘Cheating’ is not the breaking of some physiological law, but often ins a time-tested way of helping one to complete an action which is difficult to manage in a certain range of movement. Cheating Can take many forms, such as using momentum to propel a load through a ‘sticking point’, bouncing it on the body, recruiting stored elastic energy, executing only part of the movement, using synergistic muscles groups to aid the muscles which are struggling to complete the movement and using the flexibility of the equipment to flick the load through a difficult region. While cheating is to be discouraged as a regular way of training for novices, it should not be discouraged because of any belief that it is intrinsically unsafe, but because it is more advanced technique to help during certain stages of a given movement.
The safe and unsafe ways of cheating need to be taught to all trainees and not condemned without a fair appraisal of the science and the art of ‘cheating’. For example, cheat curls using a pronounced swaying and hyperextension of the truck are potentially harmful, but if cheat curls implementing an upward knee-extension thrust from a partial squat position, then the risk of back injury is minimized. Often, cheating allows one to diminish the load where it might do the most harm, so sometimes it is safer to cheat through a point of difficulty or increasing risk.
Cheating can also allow one to load muscles in a range which may be neglected if one relies solely on strict movement which forces one to use a lighter load. Thus, technically correct ‘cheating’ can be an asset to one’s training repertoire. Conversely, unskilled or premature use of cheating can pose a real threat to safety and progress.


Heavy weight training makes you bulky:
(F&F pg. 27)
This is often cited as a reason not to train with heavy weights. Many aspiring bodybuilders wish that it was that easy to produce massive hypertrophy, but the tendency to gain bulk readily is not an automatic resulting of heavy training, but depends on genetics and a very special type of sub maximal weight training. In fact, regular training with very heavy weights compels one to exercise with very few repetitions (usually 1-3 repetitions) in each set, which is know not to be the most effective way of producing muscle bulk.
Most bodybuilders have found that training with moderate to moderately heavy weights (about 60-85% of one’s maximum), rather than with maximum weight is a better way to enhance muscle hypertrophy. Moreover, the majority of the top bodybuilders use anabolic-androgenic steroids deliberately to accelerate hypertrophy, because it is the aim of their training to become massively ‘bulk’. Olympic weightlifters, on the other hand, who often train with extremely heavy weights, do not develop this enormous hypertrophy, simply because strength and power, not bulk, are the primary goals of their training.
Massive hypertrophy is not the automatic resulting of heavy weight training- instead, this is a resulting of the appropriate genetics, an appropriate training program, careful nutrition and very often, supplementation with legal and illegal ergogenic aids.




Light weight training is always safer than heavy weight training:
(F&F pg. 27)
This is common argumen for the use of insultingly light dumbbells in aerobic classes or program’s for the youngster or older adult. While it is often true that straining against near maximal loads by novices can lead to muscle strain, it is not true that safety is an automatic resulting of heavy weight training. In fact, far more injuries occur in sports and activities involving no added resistance at all, such as running, aerobics, soccer, tennis and hockey. It should be noted that light weight can even produce greater forces in the muscles than heavy weights, if they are accelerated more rapidly, according to Newton’s 2nd Law of Motion. (Force involved is proportional to the acceleration of the object.)
Moreover, a light weight acting at larger distances from the joint can produce a larger moment (moment= force X perpendicular distances from the force of joint) than heavy weight being used closer to the joint. Light weights can also be used for many more repetitions than heavy weights, so that overuse injuries becoming more likely. Finally, poor technique with light or heavy weights can have serious consequences. Magnitude offloading is not primary cause of injury; rather it is the consequence of several other factors. Sometimes, the light weight training or even training without weights (e.g. running can produce far greater impact forces on the body than heavy weight training) can be more dangerous than heavy weight training.

[Deciever]

High Intensity Training (HIT) is true high intensity training:
(F&F pg.52)
The training system known as High Intensity Training has attracted such a wide following that it has it has almost become a cult in the world of bodybuilding. Its disciples tend to be very strongly aligned against Olympic weightlifters style training, plyometrics and other forms of ballistic or explosive training, who maintain that these methods are dangerous, generally unproductive for bodybuilding purposes and redundant for most sports conditioning. By definition HIT is training whose intensity apparently is so great that it causes the trainee to suffer near the limits of his capabilities. Its proponents talk about the extended sets, with sub maximal loads rather than 1RM training, so it is obvious that their definition of high intensity is very different from the original definition which was first applied in Olympic weightlifters.
More then 40 years ago, intensity in weightlifting was quantitatively defined by Russian coaches to mean the average load lifted per repetition in any given exercise in a given workout or period, often expressed as a percentage of one’s 1RM in that exercise. High intensity training then referred to exercises performed with an intensity of a sufficiently high percentage that one’s 1RM. Along with measured of volume (total work done), intensity has long been used to cycle training loads in carefully periodised program’s.
In HIT, the key features is working as intensively or strenuously as possible, even if the actual load is only moderately heavy. In other words, HIT preferably should be called High Intensive Training to eliminate confusion between this training method and true high intensity training, as it has been technically defined for many decades. HIT is not necessarily very intense in terms of load, though it always is highly demanding, ‘intensive’, strenuous or exhausting . I doubt whether the HIT crew would have any objections to this more accurate re-definition of their acronym.
What of the value of HIT? It is superior to and safer than other methods of strength training? Not necessarily, since the effectiveness and safety of any form of exercise depends heavily on correctness of technique, suitability of loading, fatigue and mental focus, whether the exercises are done slowly, rapidly, statically or in some innovative manner.

[Deciever]

thanks so much kyle.. you really dont know how much i appreciate this.. since you put so much hard time into this... i think its deserving of a sticky position for the moment.....

[Deejay_Spike]

indeed... we love you man, real good!

[Antaeus]

pl16 - thx that was a great read!

What source did you use exactly?

And would you recommend some other works on strength training? I remember you posted a list some time ago but I can't find it...

thx,
-Ant.

[Powerlifter16]

The sources i used were from Mel Siffs books... Suertraining and Facts and Fallices. You can buy both from him. Are you talking about the list of books iam interested in that are for strength training?


lifter

[Antaeus]

thx, and yeah I just remember a post you made a long ass time ago when you rattled off like 50 books.

[Powerlifter16]

i'll do some checking and see if i can find that post.


lifter

[PLAngel]

Hello Peoples....

I found a thread that all three of my peoples are active in.... or have been active in at any rate

I want to say hello to : Kyle, Spike and Deciever

"Hello!"

[healthy n_fit]

Originally posted by PLAngel
Hello Peoples....

I found a thread that all three of my peoples are active in.... or have been active in at any rate

I want to say hello to : Kyle, Spike and Deciever

"Hello!"

Hey..what about me Angel? Now I'm active in the thread!

Ok....lol...J/k with you

[PLAngel]

Originally posted by healthy n'fit
Hey..what about me Angel? Now I'm active in the thread!

Ok....lol...J/k with you

I'm so sorry I forgot you Healthy!! I havn't talked to you in a while... and I don't talk to you over msn....

Sorry

[Powerlifter16]

Originally posted by PLAngel
I'm so sorry I forgot you Healthy!! I havn't talked to you in a while... and I don't talk to you over msn....

Sorry

OMG thats a classic!LOL


lifter

[healthy n_fit]

Originally posted by PLAngel
I'm so sorry I forgot you Healthy!! I havn't talked to you in a while... and I don't talk to you over msn....

Sorry

Lol!!!! Hey...I got MSN too...if you want to talk?

[MR MUSCLE]

Once again Kyle you have posted wome worthwhile information,i too
have msn if anybody is interested as well as aol.I would be glad to talk to other powerlifters.I aint online 24 hrs a day or anything,but be glad to.Kyle,thumbs up to u my friend.

Eric(MR MUSCLE,HardCorePowerlifter)

[Jcfreak_02]

Reading the whole thing kind of lost me on some spots, mainly all the talk about the different results form "making" fast twitch and slow twitch muscles, good read overall

[oark]

Great read. Well written. Extremely informative.

I have a question though.....maybe I didn't read close enough.....Would you say that a greater proportion of ST fibers would be beneficial to a bodybuilder? I've been a runner most of my life; lots of ST fibers.

Thanks.

[WorldMuscle]

Awesome information, thanks for digging this up fortified.

[Pro]

Originally posted by Deciever
i think its deserving of a sticky position for the moment.....

Just how long is this moment?

[ultramuscle22]

really good info but it was a little complicated at times.

[tackler]

thank yuo for this article

[waynelucky]

Hi there Deciever,
I have the book to and Mel himself did not know about h.i.t.
as why would he say this in his book, this is one with a very lot of things Mel has wrong each one i am addressing to the supertraing group, and not all about h.i.t. but the study’s, are no where to be found, and the ones i can find a lot do not add up.

In HIT, the key features is working as intensively or strenuously as possible, even if the actual load is only moderately heavy. In other words, HIT preferably should be called High Intensive Training to eliminate confusion between this training method and true high intensity training, as it has been technically defined for many decades. HIT is not necessarily very intense in terms of load, though it always is highly demanding, ‘intensive’, strenuous or exhausting . I doubt whether the HIT crew would have any objections to this more accurate re-definition of their acronym.


Well I using h.i.t. for over 15 year know how to define facts and fallacies, and this part of facts and fallacies is a fallacy,

as we here at h.i.t. use loads at 80% of our one rep max for 8 x 12 reps,
I would call that intense of load, and i would call it a bit more that moderately heavy

Thank you Wayne

[Beansent]

So what you are trying to say is that i would become more explosive and also stronger if i were to press 100kg using compensatory acceleration than if i were to press 150 kg at normal speed?

[psinide]

Hockey requires no resistance?... Ummmn, good stuff except for that...

[Footballer2409]

props, thanks for the info

[kliplemet]

OPTIMUM, NOT MAXIMUM, HYPERTROPHY

In both Olympic lifting and powerlifting, optimal and not maximal hypertrophy is a central feature of the game, unlike bodybuilding where it does not matter whether one is relatively weak or strong with reference to one's bodymass. All that matters is well-defined, symmetrical muscle bulk in bodybuilding, but in the lifting sports, your size and impressiveness of appearance earn you scant respect - all that counts is what you lift.

Optimal hypertrophy means continuing to develop building muscle only as long as that extra bulk continues to provide you with significant increases in strength and power. If you add 10kg to your bodymass and your total increases by only 5kg in a higher bodymass division, then your relative strength has decreased and that added hypertrophy is wasted on you.

This is a serious problem in contact sports such as football where the common belief is that virtually any form of added mass is good for the game (especially defensive players), whereas in reality it would be a lot better if the added bulk was mainly solid, functional muscle which added strength, power, speed and agility.

DIFFERENT TYPES OF HYPERTROPHY

Research from Russia even suggests that there are two different types of muscle hypertrophy: sarcomere hypertrophy (of the actual contractile components) and sarcoplasmic hypertrophy (of non-contractile proteins and semifluid plasma between the muscle fibres), with the latter type of hypertrophy being more in evidence in bodybuilding (Siff & Verkhoshansky "Supertraining" 1998 Ch 1.12).

MUSCLE GROWTH & PERFORMANCE

To provide some more relevant information on this important and controversial topic, I have included this fairly lengthy extract from "Supertraining" (pp 58-60) for those who may be interested:

Other research has found that hypertrophied muscle fibres need a significantly larger tissue volume to perform a given amount of work. With the development of non-functional muscle bulk(sarcoplasmic hypertrophy), the increase in muscle mass outsrtips the development of the circulatory system, resulting in decreased nutrition and oxygenation of the muscle, slowing down the metabolic processes in the muscle and less efficient disposal of metabolic waste products from the musculoskeletal system (Zalessky & Burkhanov Legkaya Atletika 1981: 1-7).

Furthermore, adaptation occurs more slowly in connective tissue (such as tendons and ligaments) than in muscle and any increased tension made possible in the musculotendinous complexes by the increased muscle mass can cause damage to these structures (Zalessky & Burkhanov, 1981). Thus, excessive hypertrophy usually leads to slower muscle recovery after exercise, deterioration in speed, speed-strength and speed, as well as an increased incidence of injury.

THE ENERGY COSTS OF TOO MUCH HYPERTROPHY

This might suggest that all muscle fibre hypertrophy lowers work capacity. Hypertrophy is an adaptive response to physical stress and does offer the benefit of increased mitochondrial surface area, which provides for more efficient energy processes than would an increased number of mitochondria.
With a rapid increase in loading, the size of the mitochondria continues to increase markedly, but their number decreases and the concentration of ATP drops, thereby diminishing the partial volume of the contractile myofibrils.

The resulting energy deficit soon inhibits the formation of new structures and the decreased amount of ATP stimulates various destructive processes associated with decrease in the number of myofibrils. This process is referred to as irrational adaptation.

Growth of any living structure is related to the balance between its volume and its surface area. When muscle hypertrophy occurs, the surface of the fibres grows more slowly than their volume and, this imbalance causes the
fibres to disintegrate and restructure in a way which preserves their original metabolic state (Nikituk & Samoilov, 1990).

It would appear that light and medium increases in loading require less energy, facilitate cell repair, minimise the occurrence of destructive processes and stimulate the synthesis of new, non-hypertrophied cellular structures. Medium loads applied with a medium rate of increase in loading produce intense muscular development, the process in this case being referred to as rational adaptation..

The fact that conventional isometric training improves performance in static, rather than dynamic, exercise may be due to the different structural effects of isometric training on the muscle fibres, muscle cells, connective tissues and blood capillaries.

MORE ON OPTIMAL HYPERTROPHY

This work seems to corroborate the hypothesis referred to earlier that there may be an optimum size for muscle fibres undergoing hypertrophy (MacDougall et al, 1982; Tesch & Larsson, 1982). The importance of prescribing resistance training regimes which produce the optimal balance between hypertrophy and specific strength then becomes obvious. Thus, it is not only prolonged cardiovascular training which can be detrimental to the acquisition of strength, but multiple fairly high repetition sets of heavy bodybuilding or circuit training routines to the point of failure may also inhibit the formation of contractile muscle fibres.

Therefore, it is vital to monitor regularly changes in muscular structure and function alongside changes in size and mass. In most cases the taking of biopsies is not possible or financially practical, so that indirect assessment of the adaptive processes is necessary. Increase in hypertrophy of a given muscle zone may be assessed from muscle girth and skinfold thicknesses at that site, while factors such as relative strength, maximal strength and the strength deficit (see Ch 1) serve as useful indicators of functional efficiency.

INDISCRIMINATE WEIGHT TRAINING

Bosco (1982a) cautions against the indiscriminate use of resistance training that typifies much of the 'cross training' prescribed with weights and circuits by Western personal trainers and coaches. He emphasizes that, although heavy resistance training serves as a powerful stimulus for the development and hypertrophy of both ST and FT fibres, the invaluable role
played by FT development can be impaired by the accompanying growth of ST fibres, because the latter appear to provoke a damping effect on FT contraction during fast movement.

This is due to the fact that, during high speed shortening of muscle, the sliding velocity of ST fibres can be too slow and therefore, may exert a significant damping effect on the overall muscle contraction. He concludes that the central role played by the storage and release of elastic energy by the connective tissues of the muscle complex should never be ignored in
sport specific training programmes.

Dr. Mel Siff

[raffiki]

Good stuff. I always say not to get pumped up using 10-15 reps, now I have more fuel.